Barack Obama's grandmother Mama Sarah Onyango Obama has died at the age of 99

• Barack Obama's grandmother has died, according to reports.
• Sarah Onyango Obama, a philanthropist, was 99 years old.
• Mama Sarah shot to national fame in Kenya upon Barack Obama's election as president in 2008.

Former President Barack Obama's step-grandmother Sarah Onyango Obama has reportedly passed away at a hospital in Kenya at the age of 99.

Known as Mama Sarah, she passed away early on Monday at a hospital in the city of Kisumu in western Kenya, her daughter Marsat Onyango told the Daily Nation newspaper.

A family spokesperson told the BBC that she had been unwell for a week but did not die from COVID-19.

Mama Sarah shot to national fame in Kenya upon Barack Obama's election as president in 2008. Tourists would visit Kogelo, the village where she lived, and often knocked on her door.

She used her fame to promote education and philanthropy, setting up the Mama Sarah Obama Foundation to provide food and education to orphans, France24 reported.

She was the third wife of Barack Obama's grandfather.

In a statement on Twitter, Kenyan President Uhuru Kenyatta said: "The passing away of Mama Sarah is a big blow to our nation. We've lost a strong, virtuous woman. A matriarch who held together the Obama family and was an icon of family values."

A spokesman for the family said she would be buried on Tuesday, the Daily Nation reported.